<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    const xiaoming = {
      name : "name1",
      height : 180,
      age : 18
    };

    xiaoming.name = 'name2';
    xiaoming.age = 19;

    xiaoming = {

    }
</script>
</body>
</html>